Hello. I have posted this elsewhere, but thought you all might like to see it as it'd be of benefit to anyone regardless of team.

Part 1:

I did a little experiment to see how much power could be saved on machines that are candidates for conversion to the GPU client, but it's applicable to most machines.

The machine tested is an Athlon 64 2.0ghz Socket 754, 256mb RAM. It's a marginal folder on most Gromacs units, and only does a little better on Ambers, so I gave consideration to swapping it's motherboard out for one that's PCI-E compatible and adding an used X1900XTX card.

So for a dedicated GPU machine, I went from 97 watts to 81 watts by undervolting. Savings of 16w. Really I went from 113 to 81, with no real change in utility for the GPU client most likely.

It appears to me that those folk with machines capable of running the GPU client, faster than 1ghz, might realize some energy savings by slowing down their processor to 1ghz and underclocking it some. Why spend money on power if it isn't necessary?

Part 2:

Final report on this system with an ATI X1900XTX and GPU client.

Here is some data, and I'll let those of you more skilled at data analysis have at it.

Using stock CPU voltage, frame time and power useage at various CPU speeds, GPU Client on an ATI X1900XTX (650core/775mem, ie, stock 3d speed).

After graphing it all up, I found that the power useage curve dropped off sharply between 1.8ghz down to 1.4ghz, and then leveled off at 1.2ghz before dropping again at 1.0. I think 1.4ghz is the sweet spot here.

Next I tried undervolting the CPU. Speed selected is 1.4ghz. Stock CPU voltage is 1.45v. I ran Orthos with a simulated Gromacs work unit to avoid corrupting the GPU client work unit if there was a Early Unit End due to crashing. I know the data isn't strictly comparable, but it gives an idea of what kind of reduction to expect with undervolting.

I left the CPU volts at 1.05v and started up the GPU client. No change in frame times, and it's been processing for an hour now with no noted instability. Total system power useage dropped to 166-168w (keeps fluctuating between the 2 readings). So I went from 207w to 168w (savings of 39w) with a modest reduction in production of 2.6% (766 Points per day to 747: 19ppd difference).

As a side note, before I did this round of testing, I purchased an Antec 430w high efficiency power supply and tested it with the system still set up for CPU Folding. Power useage dropped from 113w to 97w. This is from an older Antec power supply rated at about 70% efficiency to the claimed efficiency of around 83% with the new one). See here: http://www.silentpcreview.com/article684-page1.html

Great post. In fact, I believe the proper term for this work is that you have written an article for us.

I nominate this post for a sticky, at least until the 1900-level cards are no longer out in large quantities. In fact, thinking on it some more, I believe this article deserves a place on the front page, and I'm going to email Cyril about it.

I mentioned about that in another thread.
Basically with an older system (probably even a fast PIII) with AGP, you likely would need to upgrade the PSU for the X1950Pro AGP.
Performance of the X1950AGP 256MB is roughly 600PPD (when using 3D speeds) and the card takes quite a bit less power than other X1900 cards (and if you pick the right X1950Pro card, should be quiet as well). The X1950XTX 512MB at 3D speeds can do somewhat better (900PPD?) but initial cost (especially if need to get a new MB for it) and significantly higher power makes this option attractive primarily for those that are space limited (or that want a very fast gaming card).

Well the OP's scenario is an existing S939 system and with an X1900XTX, the PSU will need to be upgraded anyway if it could not even power the X1900XTX. So I did not include it in the cost. It will be interesting for a PIII era system nonetheless, may be worth it to do some thinking on this one too.

The Model M is not for the faint of heart. You either like them or hate them.

Actually the original system is a socket 754 board (MSI Neo Platinum) that I eventually swapped out for an Biostar board that had PCI-E on it (and voltage adjustments). It's not dead end tech if it's a dedicated folder only. I keep machines for about 3 years until they are struggling to complete work (this machine took 4+ days to finish a P2124/25, whereas my A64s (@2.4ghz) do it in 3, my C2D does one in 2 days).

I already had a proper power supply; I just wanted a more efficient one. I ended up getting a couple Antec Earthwatt 380w supplies and they are working with a X1900XTX-equipped GPU client just fine. As long as you have 30a on both 12v rails as ATI suggests, you're good to go with the X1900XTX. I can't comment on the X1950Pro series.

I'm glad someone found the info of use; it sure did reduce my electric bill. I was able to retire 2 XP2700 based systems, add on an GPU client, and am still ahead on points (not to mention saving about 190watts of power).

Actually the original system is a socket 754 board (MSI Neo Platinum) that I eventually swapped out for an Biostar board that had PCI-E on it (and voltage adjustments). It's not dead end tech if it's a dedicated folder only. I keep machines for about 3 years until they are struggling to complete work (this machine took 4+ days to finish a P2124/25, whereas my A64s (@2.4ghz) do it in 3, my C2D does one in 2 days).

I already had a proper power supply; I just wanted a more efficient one. I ended up getting a couple Antec Earthwatt 380w supplies and they are working with a X1900XTX-equipped GPU client just fine. As long as you have 30a on both 12v rails as ATI suggests, you're good to go with the X1900XTX. I can't comment on the X1950Pro series.

I'm glad someone found the info of use; it sure did reduce my electric bill. I was able to retire 2 XP2700 based systems, add on an GPU client, and am still ahead on points (not to mention saving about 190watts of power).

So if you keep the 754 CPU+board, and just grab a X1950Pro, what will be the cost/power/ppd situation be like?

The Model M is not for the faint of heart. You either like them or hate them.

Actually the original system is a socket 754 board (MSI Neo Platinum) that I eventually swapped out for an Biostar board that had PCI-E on it (and voltage adjustments). It's not dead end tech if it's a dedicated folder only. I keep machines for about 3 years until they are struggling to complete work (this machine took 4+ days to finish a P2124/25, whereas my A64s (@2.4ghz) do it in 3, my C2D does one in 2 days).

I already had a proper power supply; I just wanted a more efficient one. I ended up getting a couple Antec Earthwatt 380w supplies and they are working with a X1900XTX-equipped GPU client just fine. As long as you have 30a on both 12v rails as ATI suggests, you're good to go with the X1900XTX. I can't comment on the X1950Pro series.

I'm glad someone found the info of use; it sure did reduce my electric bill. I was able to retire 2 XP2700 based systems, add on an GPU client, and am still ahead on points (not to mention saving about 190watts of power).

So if you keep the 754 CPU+board, and just grab a X1950Pro, what will be the cost/power/ppd situation be like?

I can't say about the power situation since I don't have a 1950Pro. The X1900XTX runs about 120 watts at 3d speeds (650cpu/775mem).

The motherboard switch ended up costing me about $30 ($55 for the new board, offset by selling the old one for $25). I picked up a used X1900XTX for $275, and a X1950 runs what, a bit over $200 if you can even find an AGP version yet.

Points per day for a X1950 seems to run about 575-600 from what I read elsewhere.

RV570 are designed with 12 pipes. If it states 16 pipes and isn't a typo, it could be an X1900XT that is downclocked...?
IIRC from a TechReport review, the power use for the X1950Pro is roughly 60 watts less at load than an X1900XT

It's important. It could save many users power, and increase TR's team (that's team # 2630 for those forgetting ) output, too. I'd think it would warrant at least a "what the forums are talking about" link on the front page, if not Damage Labs or Geoff's Dungeon treatment.

Edit: I think just brew it! being on a drinking binge in Colorado is why it hasn't been stickied yet... (Just kidding JBI).

I don't see any link. Whenever someone posts in this thread, however, it will show up on the front page under Hot Threads, like any other forum posting except those in the Bargain Basement, Smoky Back Room, and R&P, and whatever moderator forums there are. Apparently 8 lines of text or subject lines is the maximum.